[Any] Prevent Fast Ladder Climb

Prevent players from climbing ladders quickly (using two directions movement to climb faster; i.e. 'wa', 'wd', 'as' or 'sd'). This is done by disabling left (a) and right (d) keys when people are climbing a ladder while using UP (w)and DOWN (s).

Why I made this plugin :

Just saw that other plugin here which adressed that problem, but was for L4D only and aimed at other different fixes. So this one is for any mod that has ladders. It uses almost the same method (mine corrected a bug that I'm reporting as I write these lines).

It can be annoying when people climb at different speed (like when you move too quickly, and you are blocked by a noob who doesn't know how to climb quickly; or when you climb a ladder too quickly and do a little jump in the air and get stuck on someone's head). I believe this solve (ungracefully :/) the problem.